Search Results (7)

Mining activities have a significant impact on the quality of river water in the Roșia Montană area. This region, known for its gold and other precious metal mining, serves as an example of the interaction between anthropogenic activities and the natural environment. Water from mine drainage is metal-rich and contaminates the environment, inhibiting the growth and reproduction of aquatic plants and animals, while also having corrosive effects on infrastructure. As part of the study, parameters such as pH, dissolved oxygen, biochemical oxygen demand, chemical oxygen demand, sulfates, and heavy metals were monitored for the rivers in the area (Roșia Montană, Săliște, Corna, Abrud, and Arieș). Roșia Montană river shows a decrease in pH to highly acidic values (2.69–3.95), especially in the downstream sections. Sulfate concentrations exceed 3600 mg/L, and heavy metal concentrations (Fe, Zn, As, Mn) increase significantly, indicating severe pollution, primarily originating from the Gura Mine gallery. These frequently exceed the thresholds corresponding to water quality classes I and II, and in some cases even surpass the limits of class V (the most polluted). The presence of As (27.60 µg/L) in Roșia Montană River indicates a significant ecotoxicological risk. In an attempt to treat the acid mine drainage from Roșia Montană, a natural zeolite was used at different doses. The results obtained show good efficiency of zeolite in removing the metal ions (Fe, Zn, and Mn). The results provide valuable information on the quality of river waters in the mining area of Roșia Montană and suggest that zeolite can be used effectively to decontaminate mine waters. Full article

We investigated the diatom communities and physicochemical water variables in the Abrud River catchment area (the Roșia Montană mining area, Romania) at 16 sampling sites, some of them impacted by acid mine drainage (AMD) and heavy metals. Diatoms serve as effective indicators of water characteristics owing to their ubiquity and sensitivity to environmental variables. This study aimed to enhance the understanding of the key environmental factors influencing the diatom flora of polluted rivers across various spatial and temporal scales, thereby informing the optimization of ecosystem management strategies. This work contributes to the knowledge of Romanian diatom flora through the identification of 274 taxa belonging to 63 genera, including 35 taxa recorded for the first time in the country. The spatial and temporal variations in the species richness patterns highlighted the effects of water pollution resulting from past mining activities, revealing distinctions between the main Abrud River stream and its tributaries, some of which exhibited extremely low species richness with few or no identified taxa. This contrasted sharply with the cleaner upstream waters of the Roșia Valley, where a notably rich diatom community (85 taxa) persisted, highlighting the severe localized impact of mining discharges on biodiversity. Full article

Pollution in mining areas represents a major environmental issue, significantly impacting ecosystems and human health. This study highlights propolis as an efficient natural bioindicator for detecting and assessing the degree of contamination in these areas. The objective of this study is to determine the levels of metals (Pb, Cd, As, Cr, Fe, Mn, Cu, and Zn) in propolis from mining exploitation areas in Romania, specifically in the counties of Alba, Hunedoara, Maramureș, and Caraș-Severin. Although mining operations are closed, the anthropogenic impact varies due to differences in the surface areas of the zones affected, the areas occupied by waste heaps, local hydrological conditions, and partial ecological rehabilitation efforts. To highlight the impact of contamination, a reference area considered unaffected by anthropogenic activities was used as a benchmark for each county. The values obtained in the investigated area were compared with those from this control zone to determine the differences and the specific impact of pollution. Maximum values were recorded in Roșia Montană for Pb (9.27 mg·kg⁻¹), Cd (0.17 mg·kg⁻¹), and As (0.87 mg·kg⁻¹); in Băile Borșa for Fe (150.23 mg·kg⁻¹) and Zn (2.9 mg·kg⁻¹); in Certeju de Sus for Cu (6 mg·kg⁻¹) and Cr (7.01 mg·kg⁻¹); and in Moldova Nouă for Mn (25.43 mg·kg⁻¹). The maximum content values of phenols (189.49 mg·kg⁻¹ in Alba County) and flavonoids (88.06 mg·kg⁻¹ in Caraș-Severin) were recorded, as well as the minimum IC₅₀ antioxidant activity (0.33 µg·mL⁻¹). Propolis from these areas showed antimicrobial activity against five bacterial strains (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, and Streptococcus mutans) and five fungal strains (Candida albicans, Aspergillus niger, Aspergillus flavus, Cryptococcus neoformans, and Penicillium chrysogenum), although such antimicrobial and antifungal activities were more intense in unpolluted areas. The present study reveals that propolis is a natural indicator of heavy metal pollution in mining areas. These data support the usefulness of propolis due to its high capacity to accumulate and reflect environmental contaminants. Full article

Contamination with heavy metal ions from mining activities presents a major environmental issue. This study investigates pollution caused by heavy metals from mining, with a particular emphasis on toxic ions and essential ions for living organisms. It starts by analyzing the sources of pollution and its effects on soil, vegetation, water, and wildlife (propolis produced by honey bees living in natural environments). Propolis is an indicator of environmental contamination by metals, a natural and valuable product of natural ecosystems. As part of the investigation, the contamination with metal cations (Pb²⁺, Cu²⁺, Cd²⁺, Zn²⁺, As³⁺, Fe²⁺, and Sr²⁺) of the soil, cultivated vegetables (carrot, turnip, onion, potato) was monitored in 9 points in the Roșia Montană area, Romania, as well as the river that runs through the area. The maximum values of the parameters investigated were recorded in soil (108.32 mg/kg Pb²⁺, 23.06 mg/kg Cd²⁺, 102.17 mg/kg As³⁺), river water (11.00 µg/L Pb²⁺, 903.47 µg/L Cu²⁺, 60.13 µg/L Cd²⁺, 1903.08 µg/L Zn²⁺, 148.07 µg/L As³⁺, 44,024.08 µg/L Fe²⁺), vegetables (0.72 mg/kg Pb²⁺, 0.17 mg/kg Cd²⁺) and it was followed whether the same heavy metals are found in propolis (maximum values 10.14 mg/kg Pb²⁺, 6.32 mg/kg Cu²⁺, 0.158 mg/kg Cd²⁺, 6.0 Zn²⁺, 1.04 mg/kg As³⁺, 12.06 mg/kg Sr²⁺). The parameters analyzed for the river waters were pH, sulfates, the oxygen and nutrient regime, and microbial load. Additional investigations were carried out into the quality of these propolis samples: water activity, moisture, hygroscopicity, water solubility, volatile oils, oxidation index, measuring point, density, dry matter, material insoluble in ethanol, extractable with ethanol, ash, and wax. The highest values were 189.4 mg GAE/g for phenols, 84.31 mg QE/g for flavonoids, and 0.086 µg/mL for IC₅₀ antioxidant activity. This study indicates that bee products, such as propolis, can be an indicator of pollution in mining areas. Full article

Worldwide, concerns about heavy metal contamination from manmade and natural sources have increased in recent decades. Metals released into the environment threaten human health, mostly due to their integration into the food chain and persistence. Nature offers a large range of materials with different functionalities, providing also a source of inspiration for scientists working in the field of material synthesis. In the current study, a new type of copolymer is introduced, which was synthesized for the first time by combining chitosan and poly(benzofurane-co-arylacetic acid), for use in the adsorption of toxic heavy metals. Such naturally derived materials can be easily and inexpensively synthesized and separated by simple filtration, thus becoming an attractive alternative solution for wastewater treatment. The new copolymer was investigated by solid-state nuclear magnetic resonance, thermogravimetric analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photon electron microscopy. Flame atomic absorption spectrometry was utilized to measure heavy metal concentrations in the investigated samples. Equilibrium isotherms, kinetic 3D models, and artificial neural networks were applied to the experimental data to characterize the adsorption process. Additional adsorption experiments were performed using metal-contaminated water samples collected in two seasons (summer and winter) from two former mining areas in Romania (Roșia Montană and Novăț-Borșa). The results demonstrated high (51–97%) adsorption efficiency for Pb and excellent (95–100%) for Cd, after testing on stock solutions and contaminated water samples. The recyclability study of the copolymer indicated that the removal efficiency decreased to 89% for Pb and 58% for Cd after seven adsorption–desorption cycles. Full article

We evaluated the significance of the iron and manganese content in sphalerite as a tool for distinguishing between low-sulfidation and intermediate-sulfidation epithermal deposits on the basis of new and previously published electron probe microanalyses data on the Roșia Montană epithermal ore deposit and available microchemical data from the Neogene epithermal ore deposits located in the Apuseni Mountains and Baia Mare region, Romania. Two compositional trends of the Fe vs. Mn content in sphalerite were delineated, a Fe-dominant and a Mn-dominant, which are poor in Mn and Fe, respectively. The overlapping compositional range of Fe and Mn in sphalerite in low-sulfidation and intermediate-sulfidation ores suggests that these microchemical parameters are not a reliable tool for distinguishing these epithermal mineralization styles. Full article

The need and estimated utility for a structured analysis of the Roşia Montană gold exploitation project have been palpable in the Romanian public sphere during the last 15 years and there is a vast amount of conflicting information and opinions on the benefits and risks involved. This article provides a comprehensive decision analysis of the Roşia Montană project. Over 100 documents from the past years have been gathered regarding the Roşia Montană mining project, which cover the main official, formal and less formal documents covering the case and produced by a wide range of stakeholders. These were then analyzed while designing a multi-criteria tree including the relevant perspectives under which the most commonly discussed four alternatives were analyzed. The result of this can be translated into a valuable recommendation for the mining company and for the political decision-makers. If these stakeholders want the continuation of the project and its acceptance by civil society, the key challenge is to increase the transparency of the process and improve the credibility and legal aspects; if these aspects cannot be met, the decision-makers need to pay attention to the alternatives available for a sustainable development in the area. Full article